Vacuum annealing decomposition of graphene on Cu studied by in situ photoelectron spectroscopy

Cu表面上でのグラフェンの真空中加熱分解のその場光電子分光

小川 修一*; 山田 貴壽*; 石塚 眞治*; 吉越 章隆 ; 長谷川 雅考*; 寺岡 有殿; 高桑 雄二*

Ogawa, Shuichi*; Yamada, Takatoshi*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Hasegawa, Masataka*; Teraoka, Yuden; Takakuwa, Yuji*

In this study, we have investigated the graphene segregation and decomposition processes on Cu(111) substrates by photoelectron spectroscopy using synchrotron radiation. The photoelectron spectroscopy was performed at BL23SU of SPring-8. The sample was epitaxially grown graphene/Cu(111)/AlO(0001). At 373 K, strong O1s peak was observed, derived from adsorbed HO and Cu oxide. The O1s intensity decreases with increasing temperature, and disappears at 853 K. The C1s intensity also decreases with temperature increase, indicating that the O atoms are removed as CO or CO molecules. For further annealing over 873 K, C1s intensity continued to decrease, indicating that the graphene is decomposed and C atoms diffuse into the Cu substrate. When the sample was cooled down after annealing at 1223 K, C1s intensity did not recover.